retention-time: exact dates for wraparound needed

What the extended date range mechanism is

Data ONTAP denotes time as a signed 32-bit integer that is interpreted as the number of seconds since 1 January 1970, 00 hours 00 minutes 00 seconds (GMT). This interpretation imposes an upper limit of 03 hours 14 minutes 07 seconds on 19 January 2038 (GMT). The extended date range mechanism remaps the dates in the range 2038 to 2071 to the date range 1970 to 2003.

To support an extended range for record retention dates, SnapLock provides a mechanism by which applications can specify retention dates up to 19 January 2071 (GMT). This is accomplished by defining a new epoch for the last access time of 1 January 2003 00 hours 00 minutes 00 seconds (GMT). Instead of setting off the entire time range, the last access times before 1 January 2003 (GMT) are interpreted as dates in the future, using a wraparound technique. Therefore, all retention dates between 1 January 2003 and 19 January 2003 remain identical to the regular format. However, the dates between 1 January 2038 and 19 January 2071 are encoded as past dates.

For example, a file with a record retention date of 1 January 2040 displays the retention date as 1 January 1972.

My question is - what is the exact mapping? Maps the 1 January 1970 to 1 January 2038 and the 1 April 2038 to 1 April1970? And 10 January 1970 is exactly the same as 10 January 2038 and mapping is optional up to 19 January 2038?

But I also read in a paper title Data ONTAP 7.3 - Archive and Compliance Management Guide on Page 65:

is-wraparound: is displayed if the date represented in retention-time is in wraparound

format. The wraparound format indicates that dates after 01/19/2038 are mapped from

01/01/1970-12/31/2002 to 1/19/2038-01/19/2071.

which indicates to me, that 19 January 2038 is mapped to 1 January 1970.

So what is correct? Is 1 Januar 1970 equivalent to 1 January 2038 or equivalent to 19 January 2038?

Re: retention-time: exact dates for wraparound needed

‎2012-03-2301:22 PM

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